private void SetBackgroundImage(Bitmap originalBackgroundImage) { _resizedBackgroundImage = ExportPngXml.ResizeBitmap(originalBackgroundImage, VideoWidth, VideoHeight); var bmp = new Bitmap(_resizedBackgroundImage); using (var g = Graphics.FromImage(bmp)) { g.DrawRectangle(Pens.Green, Convert.ToInt32(comboBoxLeftRightMargin.SelectedIndex), VideoHeight - CdgGraphics.FullHeight - Convert.ToInt32(comboBoxBottomMargin.SelectedIndex), CdgGraphics.FullWidth, CdgGraphics.FullHeight); } var oldBitmap = pictureBoxBackgroundImage.Image as Bitmap; pictureBoxBackgroundImage.Image = bmp; oldBitmap?.Dispose(); }